DS1302S+

Overview

The DS1302S+ is a low-power real-time clock (RTC) and calendar integrated circuit manufactured by Analog Devices Inc./Maxim Integrated. It provides seconds, minutes, hours, date, month, day of the week, and year information with leap-year compensation valid through 2100. The device features 31 bytes of battery-backed static RAM and communicates via a simple 3-wire serial interface compatible with most microcontrollers. Operating on a supply voltage of 2V to 5.5V, it consumes less than 300nA at 2.0V. The component is housed in an 8-pin SOIC package (208 mils width) and supports commercial temperature operation from 0°C to +70°C.

Feature Summary

• Real-time clock/calendar with leap-year compensation valid up to 2100
• 31-byte battery-backed general-purpose RAM
• Simple 3-wire synchronous serial interface (CE, I/O, SCLK)
• Programmable trickle charger for backup battery or supercapacitor charging

Applications

• Embedded systems requiring precise timekeeping
• Data logging devices needing non-volatile storage
• Battery-operated consumer electronics
• Industrial control systems with commercial temperature requirements

Procurement Notes

Verify that the specific order corresponds to the 'S' suffix variant, which denotes the 8-pin SOIC (208 mils) package. Confirm the operating temperature range requirement matches the commercial grade (0°C to +70°C), as industrial variants (-40°C to +85°C) utilize different suffixes such as 'SN'. Ensure compatibility with the required PCB footprint for the 8-SOIC package.

Selection Notes

Select this component when a 3-wire serial interface is preferred over I2C or SPI protocols. The DS1302S+ is suitable for applications requiring a wide supply voltage range (2V–5.5V) and low standby current. Note that the internal oscillator requires an external 32.768kHz crystal with a specified load capacitance of 6pF. For designs requiring extended temperature ranges, consider the DS1302SN+ instead.

Part Context

The DS1302 series serves as a successor to the DS1202, offering enhanced features such as dual power pins for primary and backup supplies and a programmable trickle charger. The 'S' suffix specifically identifies the standard-width 8-pin SOIC package (208 mils). Other variants include the narrow SOIC ('Z') and DIP packages ('P'), available in both commercial and industrial temperature grades.

Replacement Considerations

For industrial temperature range requirements (-40°C to +85°C) in the same package, use DS1302SN+. For narrow SOIC packages, consider DS1302Z+ (commercial) or DS1302ZN+ (industrial). Direct pin-compatible replacements with different interfaces, such as the DS1307 (I2C), require software and schematic modifications.